Water closets and their associated water closet rings have, of course, been in use for many years and secure the water closet to its associated drain pipe. The time accepted procedure using cast iron pipes has been to place the closet ring about the pipe so that it rests on the floor of the room and then fill in the tapered area between such pipe and such ring with lead and oakum to seal the two together.
With the advent of plastic drain pipe, lead and oakum could no longer be used because when heated to a liquid state, it would melt the pipe adjacent the ring.
Various arrangements have been experimented with to meet changing product requirements including the use of sealants other than lead and oakum. None of these substitute sealing means between water closet ring and drain pipe until now have been as satisfactory as lead and oakum in conjunction with cast iron pipe.